Robin Roberts: 'GMA' Anchor Celebrates 'Major Milestone'

"Good Morning America" co-anchor Robin Roberts got an early start on her New Year's celebrations, marking a "major milestone" in her recovery from the bone marrow transplant she underwent in September.

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(Courtesy: Twitter/Robin Roberts)

"Every morning I mark the day post my bone marrow transplant. Today I reached a major milestone…Day 100! Blessings..XO," Roberts, 52, tweeted this weekend, along with a picture of herself clad in a Santa hat in front of a Christmas tree decorated with an ornament that said "Faith."

Just days after celebrating her milestone, Roberts took to Facebook to wish all those who have supported her over the past year a happy New Year.

"I couldn't let the year end without saying…thank you. Thank you for your prayers, positive energy and well wishes," she wrote. "My sister, Dorothy, always comes up with a family motto for the new year. This year's is: "All will be serene in 2013."

w disorder that affects blood-cell production. The transplant was a five-minute procedure in which the donor cells from Robin's sister, Sally-Ann, were injected into Robin's system through a syringe.

On the heels of her 100-day milestone, Roberts also got a belated Christmas present, welcoming her beloved Jack Russell terrier, K.J., back home. They were separated because of Roberts' weakened immune system.

"Look who made it back for my 100 day celebration…KJ!! We just keep staring at each..can't believe she's finally home," Roberts tweeted Saturday.